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Delmopinol Hydrochloride Side Effects In Dogs

What is Delmopinol Hydrochloride?

Delmopinol HCl Side Effects in DogsDelmopinol hydrochloride (HCL) is a compound that has been shown to reduce the amount of plaque and gingivitis formation on teeth during clinical trials in humans. The study also compared Delmopinol HCL to other known plaque reducing mouthwash compounds and patients reported less irritation and side effects compared to the alternative.

A form of Delmopinol has been approved by the FDA for human use for prevention of plaque gingivitis and has been claimed to provide similar results for dogs. As per the description given by the FDA; "The drug interacts with the early acquired pellicle, the thin layer of saliva polymers and proteins covering teeth and gums, and forms a barrier over teeth and gums. This barrier prevents the microbial adhesion and colonisation on the tooth and gum surface. Delmopinol itself has no bactericidal activity."

What is Plaque?

Plaque is a combination of bacteria and slime that forms a film coating on teeth – if left for too long, plaque will harden into tartar which can cause damage to the teeth and gums. Even before tartar forms, plaque can cause problems because of the bacteria it traps on teeth and in the mouth. Bacteria is what gives your dog stinky breath and can result in other teeth, mouth or gum related problems.

Cleaning plaque and managing your dog's dental hygiene

Classic ways of removing plaque and bacteria from your dog’s teeth include manual brushing or having them play with specifically shaped chew toys which can scrape away the plaque. Delmopinol hydrochloride has been proposed to support mechanical cleaning by forming a protective barrier on your dog’s teeth to help repel plaque. This was first introduced in 2015 when Merial launched their line of OraVet Dental Hygiene Chews, which claim to improve canine dental hygiene and have support from vets. As mentioned, the formation of plaque, tartar and bacteria contribute to the unkind breath your dog might have, but it can also cause gum recession, inflammation and tooth loss if left unchecked.

OraVet Chews carry a seal of approval from the Veterinary Oral Health Council (VOHC). OraVet also claims to be supported by research that shows dental hygiene improvements where a comparison trial of giving dogs one OraVet chew per day versus dogs on a diet of dry food showed a plaque and tartar reduction of 50% in the OraVet group – however, the actual study is not published. OraVet Chews do however have many positive reviews around the internet with 4-5 stars given by customers from most major pet stores and minimal complaints or reports of irritation.

Side effects of Delmopinol Hydrochloride

Unfortunately, no studies have been done specifically on the side effects of delmopinol hydrochloride ingested by dogs, but people have mentioned some side effects for OraVet Hygiene Chews. Feedback shows the Chews can sometimes lead to diarrhoea or vomiting, but mostly limited to dogs with sensitive stomachs.

There have also been reports that OraVet Chews have turned some dog’s stool green – as strange as this may look, it is likely not to cause any harm to your dog, and is caused by ingredients in OraVet other than delmopinol hydrochloride such as the parsley flakes and alfalfa.

It should also be noted that the effectiveness of the OraVet Chews (and any other breath freshening chews) will be lost if your dog swallows the chew whole (the chewing action is what spreads the active ingredients around your dog’s mouth) so should be monitored.

Alternative dog chews

Other well-known dog chew treats include;

These alternatives do not contain delmopinol hydrochloride – so might be worth checking out if you’re sceptical on that chemical specifically.

A majority of the reviews given by consumers for OraVet Chews are positive, and there is no known specifically adverse side-effects due to delmopinol hydrochloride across the general population of dogs that are given the Chews. Delmopinol hydrochloride itself has known benefits to reduction of tartar, plaque and bacteria on teeth and gums – but as always there are alternatives if you’re still cautious.


  • Hi my dog has pancreatitis and had a severe attack and is now on a very strict script food diet with no treats as they are high in fats and contain salt. My question is will these be safe for him to eat as I know low fat diet is very important for him. He has bad breath and is an old dog so I need something that is safe for him to help with his teeth. A lady working at a Vet Chemist said these are very low in fat but wanted to check first.
    Thanks Debbie

    Debbie Gleave
  • The fat content of these chews is 2.55% (which as you mentioned is quite low), I’ve added a quick summary below – but please also check with your vet to make sure these are suitable and can fit with your dog’s diet.

    OraVet Dental Hygiene Chews fat content per chew:
    Extra-small: 0.3 grams
    Small: 0.51 grams
    Medium: 0.8 grams
    Large: 1.31 grams

    Kind regards,

    Jones Everton
  • Thank you for this post. My vet recently suggested OraVet chews and my dog (mini dachshund) is also elderly with pancreatitis. She loves them, has had no adverse reaction and they have definitely improved her breath. When she was younger (before I knew better and before OraVet chews were on the market), the vet said the chews I gave her then had probably contributed to her pancreatitis so I’m very pleased with these chews. Hope this helps.

    Janice DiRose
  • What chews contributed to her pancreatitis? How long has your dachshund been using the OraVet chews?

  • We started giving our two, five year old, rescue dogs Oravet Chews about 6 months ago. Last week one of my girls threw it up overnight-and threw up three more times within an hour, and had horrible gas-my girls never have gas due to high quality, minimal ingredients food. This was definitely what made her sick, the color was a match with the first throw up. We did not connect it until we gave her another, 5-6 days after the initial incident, and she threw up in her crate during the night again. It looked exactly the same as the first episode from a week earlier, and green, just like the chew. We only give them the chews every other day, or longer, so they don’t get overloaded, but my one dog obviously has developed an issue with them. I hope that there isn’t parmanent intestinal damage from this.


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